Bag elevator



`lune 6, 1961 Filed Dec. 19, 1958 GRAY BAG ELEVATOR 3 Sheets-Sheet l F. P. GRAY BAG ELEVATOR June 6, 1961 3 Sheets-Sheet 3 Filed Dec. 19, 1958 INVENTOR. FRANK/ 0V faqr ATTORNEYS 2,987,166 BAG ELEVATOR 'A I Franklin P. Gray, 2600 E. Flora Place, Denver, Colo.

Filed Dec. 19, 1958, Ser. No. 781,735 16 Claims. (Cl. 198-l65) and unpackaged materials rapidly and economically.

Also, their construction makes it possible to design units which can be curved, arched, twisted and generally adapted to perform various troublesome conveying functions that are impossible, or at least extremely difficult, to achieve with other types of conveyors.

Perhaps the most significant `advantage of the spring belt driven conveyor, however, is its ability to handle bulk granular or powdered materials packaged in paper or cloth bags without damaging the container and spilling the contents. Of course, wide fabric belt conveyors can accomplish this same function, but, their use is generally limited to straight runs with little or no slope above or below horizontal. The spring belt conveyor, on the other hand, is not limited in its application to straight and relatively level conveying operations.

In addition, spring belt driven units can be designed which will elevate filled Ibags vertically as they are received from a horizontal conveyor section while performing the incidental, but important, added function of flattening the packages. Few, if any, of the other well known types of conveyors can flatten and elevate the bags .at the same time although at, uniform packages are quite essential to economical storage and proper loading for transportation.

Unfortunately, however, certain diilicultes have arisen in connection with the design of spring belt driven bag elevators for use in handling filled bags. The basic problem lies in the considerable non-uniformity of the packages that must be raised in the elevator without damage to the bag. Granular or powdered materials obviously tend to fall and concentrate in the bottom of the bag as it is turned up on end thus producing a somewhat teardrop-shaped package that is quite likely to tear as it moves between the opposed conveyor belts. Also, many factors that are extremely difficult to control influence the shape of the individual packages which may vary considerably from one to another.

lt has now been found, however, in accordance with the teachings of the instant invention that the aforementioned difliculties can be overcome through the novel expedient of providing the bag elevator with a yieldable frame section spring-biased toward a fixed frame section. Hydraulically-actuated means are also included for changing the spacing between the fixed and yieldable Iframe sections and also for varying the degree of springbias of the yieldable frame section against the bags in order to hold them securely without slipping yet prevent- -ing the bags from becoming torn. These desirable ends are realized by reason of a novel and yet simple hydraulically-actuated link assembly interconnecting the fixed and yieldable frame sections in a manner to compensate for lnon-uniform packages and different bag thicknesses. The bag-flattening assembly is also provided with manuallyoperable adjustmentmeans for use in varying the spacfing between a oating and rigid frame section to accommodate vdifferent bag sizes and oversize non-uniform gpackages delivered thereto from a levelconveyor.

ted States Patent- It is, therefore, the principal object of the present invention to provide a novel and improved spring belt driven bag elevator. I

A second object is the provision of a bag-elevating device which also flattens the filled bags preparatory to elevating them thus providing for most eicient transportation and storage thereof.

A third object of the invention is to provide a baghandling apparatus that includes a novel yieldable frame assembly which automatically conforms with variations in package shape and thickness thereby substantially eliminating any bag-tearing problems.

Another object is to provide a gravityoperated bag attener which includes an adjustable floating conveyor frame operatively associated with the yieldable frame l of a bag elevator.

Still another object is to provide a device ofthe claSs described which is readily adjustable to receive, flatten and elevate lled bags of many different thicknesses.

Further objects are to provide a bag elevator vwhich is relatively simple, compact, rugged, versatile, easyk to service, inexpensive, and one that is adaptable for use in a wide Variety of different conveyor applications.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follow, andin which:

FIGURES lA and 1B are a composite side elevation of the spring belt driven bag elevator that comprises the present invention, FIGURE 1B being the Vupper end of the unit shown in 1A; v

FIGURE 2 is a fragmentary transverse section to an enlarged scale taken along line 2-2 of FIGURE 1A, portions thereof having been broken away to better show the construction;

FIGURE 3 is a fragmentary side elevation showing the bell crank portion of the link assembly as illustrated in FIGURE 2;

FIGURE 4 is a fragmentary transverse section to an enlarged scale taken along line 4 4 of FIGURE 1A illustrating one of the rolling supports for the yieldable frame section;

FIGURE 5 is a fragmentary transverse section to. an enlarged scale taken along line 5 5 of FIGURE 1B showing one of the sliding supports for lthe yieldable frame section;

. FIGURE 6 is a section taken along line 6-6 of FIG- URE 2;

FIGURE 7 is an enlarged fragmentary elevation illustrating the pivotal connection between the piston of the hydraulic cylinder and the bell crank of the link assembly; and

FIGURE 8 is a fragmentary section taken along line 8-8 of FIGURE 5.

Referring now to the drawing and in particular to FIGURES 1A and 1B thereof, the bag elevator of the present invention will be seen to comprise a fixed frame, indicated in a general way by numeral l0, which includes a horizontal section 12 at the intake end, an inclined intermediate section 14 and an upright section 16 at the discharge end; a curved oating frame section, referred to broadly by numeral 18, arranged in spaced relation to the inclined section of the fixed frame and including a plurality of hingedly interconnected frame segments 20; and, a rigid but yieldable frame section, generally designated by 22, operatively connected to theloating frame and arranged in spaced relation to the upright section of the tixed frame. More specifica1ly,the horizontal section 12 of the fixed frame 1l) is, in the particular embodiment illustrated herein, formed from a pair of ground-supported horizontal side frame elements 24 'arranged in transversely spaced substantially parallel re l a tion which are interconnected by transverse frame eleagentes Nfranja; elements 24 of the horizontal frace section function to maintain the floating frame section 1S centered 4`therebetween and over the inclined section 14 of the fixed frame. l

Similarly, the upright section 16 ofthe fixed frame, as illustrated herein, comprises four ground-supported upright side frame elements having their lower endsv attached to the rear ends of horizontal side frameelements 24. These four upright side frame elements arel arl ranged in transversely spaced substantially parallel pairs, each pair of which includes a front upright side frame element 34 and a rear 'upright side. frame element 36.

Suitable braces 38 interconnect the front; andv rearside `frame elements 34 and 36 of eachpair-while tubular `elements 26, aforementioned, function to maintain elements 34 in fixed spaced relation.

The. inclined section 14 of the fixed frame, on the other hand, comprises merely a transversely spaced 'pair ofe'diagonal elements 40 attached between the elements 28 and34 of the horizontal and upright frame sections, respectively. In this specific embodiment of the invention, the middle grooved roller 30 carried bythe inclined frame section 14 of the fixed frame is journalled for rotation about a transverse axis offset beneath the plane containing the axes of rotation of the rollers on either slide thereof which are mounted between side plates 42 carried by diagonal element 40. Note, also, that each of the tubular elements 26 is located such that it is substantially tangent to the inside of the endless spring belts 28 stretched between adjacent `grooved rollers 30 on the inside edges of the respective frame sections, the elements 26 carried by diagonal elements I40 of the inclined frame section being suitably elevated on lugs 44 along with the adjacent tubular elements carried by the horizontal and upright frame sections.

. Reference will now be had to FIGURES 1A, 1B

and 4'for a detailed description of the construction and means by which the yieldable frame section 22 is mounted for rolling movement relative to the fixed frame 10. First of all, yieldable frame section 22 will be seen to include two upright side frame. elements 46 arranged in transversely spaced substantially parallel relation to one another and interconnected by tubular elements 26. At longitudinally spaced points along upright frame section 16v of the rigid frame, a pair of spaced substantially ,parallel rails 48 are attached to the front upright side Vframe element 34 in position to extend forwardly therefrom where their free ends are connected together by transverse element 50 which is welded or otherwise permanently attached therebetween in position to form a closure for the front end of roller track 52. Rollers 54 mountedV for rotation on axles 56 projecting outwardly from the sides of frame elements 46 of the yieldable frame section, roll back and forth on rails 48 Within track 52 thus providing for relative movement between the yieldable and fixed frames.

It will also be seen in Figures 1A, 1B, 5 and 8 that side frame elements 34 and 46 of the yieldable and uprighty frame sections, respectively, also include other transverse tubular elements 58 similar to elements 26 but arranged in opposed parallel relation to one another at longitudinally spaced points above and below rails 48. Mounted for rotation in each of these tubular elements 58 is a smaller tubular element 60 projecting slightly beyond the ends thereof. The ends of the tube 60 mounted inside'tube 58 carried by the upright frame are attached to 1a pairl of transversely spaced forwardly extending tubes 62 thatgare slidably mounted in short tubular sections 64 i on the endsof the other tubular element 58 connected v to "nie yieldablefrme. In ademen, the front ends of tubes Yscale 68 can be mounted on one of the tubes 62 for movement relative to an index 70 carried by element 64 to indicate the spacing between the fixed and yieldable frames.

Again referring to FIGURE 1A of the drawing, the oating framevsection 18 will be seen to have its upper end hingedly connected to the lower 'end of the-yieldable frameY section for relative movement toward and away from the inclined fixed frame section 14. Note, however, thatthis is the only connection for the oating frame, all of the hinged segments 20 thereof," except for thepivotal connections therebetween, merely resting upon plates 72 carried on the upper ends ofrods 74 which are adjustably mounted on the diagonal elements 40 of the inclined frame section 14 by means of thumb screws and rod brackets 76. These adjustable rods and plates determine the spacing between the endless spring belts carried by the floating and inclined frame sections in order to accommodate filled bags of different thicknesses; however, it is important to note in this connection that the .by pressing on theY filled bags performs a preliminary bag-flattening function that is completed when the packages pass between the yieldable and upright frame sections.

The spring-biased link assembly which has-been designated generally by numeral 78 and which functions to Vcontrol the spacing between the yieldable and upright frame sections by means of a yieldableconnection, can best be seen in FIGURES lA, 1B, 2 and 3 to which reference will now be had. A pair of rearwardly exytendingbrackets 80 are attached to the outside of the .front side frame elements 34 of the upright section of the fixed frame in transversely spaced relation and at various points throughout its length; Each pair of brackets is interconnected by an inner tubular element S2 that forms a hollow shaft upon which a bell crank assembly turns. This bell crank assembly includesxan outer tubular element 84 mounted on element 82'for rotational movement and a pair of bell cranks 86 welded or otherwise permanently attached to opposite ends of the outer tubular element for conjoint rotation therewith. rlhe legs 88 of the bell cranks are interconnected by an inner tube 90 while the other legs 92 are similarly connected by an outer tube 94. Each of the outer tubes 94 includes mounted for rot-ation therein an inner tube 96 that projects slightly beyond the opposite ends thereof.

It will also be seen, especially in FIGURE 2, that elements 46 of the yieldable frame section are interconnected by transverse tubular elements58 having-smaller tubular elements 60 rotatably mounted inside thereof in substantially the same manner ashas already been described in connection with FIGURES of the drawings; however, tubes 58 and 60'in this instance are located'opposite the tubes which interconnect arms 92 of the bell cranks S45-'and connecting rods 98'` are substituted' for the short tubularmembers64 on the ends of tube60. Rods v91,8 interconnect tubes'6i) and'n96fpas'singp`1jth`rdu'gh suitabieopenings4 therein. f Fixed sediments "100 are'ar- ,ried by rods 98 lapping tube 60 and ahead o f tube 96 in spaced relationto nut 102 on the rear end thereof A compression spring 104 having washers at vopposite ends thereof is mounted on the rear end of each rod 98 between tube 96 and nut 102. Thus, rotational movement of the bell crank assembly on hollow shaft 82 will cause the yieldable frame section 22 to move toward or away thand, it is the spring-biased yieldable connection between tubes 60 and 96 when tube 96 is xed that provides for limited relative movement between the frame sections `22 and 16 to compensate for variations in the size of the individual packages. As an overilled bagv that is slightly thicker than the rest passes into position between frame sections 22 and 16, rods 9S become extended compressing spring 104 and allowing these frame sections to separate farther which, of course, permits the bag to move therethrough without tearing. In actual operation, the spring belt conveyor assemblies carried by the xed and yieldable frames are spaced apart by the bell crank assembly a distance slightly less than the minimum thickness of the filled bags so that springs 104 are compressed slightly at all times during the elevating operation in order that the packages cannot slip down and also to complete the bagattening operation.

Referring now to FIGURES 1A, 1B, 2, 3, 6, 7 and 8, the hydraulically-operated actuating mechanism, indicated broadly by numeral 106, which is used to operate the link assembly 78 will be seen tovinclude a hydraulic cylinder 108 pivotally mounted on one of the cross frame elements of the fixed frame and having a piston 110 mounted therein for reciprocal movement that is pivotally connected to tube 112 that interconnects the extended legs 88m of one of the pairs of bell cranks 86m.. Fluid lines 114 connected into opposite ends of the hydraulic Acylinder are, in turn, connected to means (not shown) of conventional design operative to reverse the direction of uid ow to the cylinder such as, for example, a reversible pump or preferably a pump and, valve combination including a by-pass connection; Each of the inner tubular elements 90 which interconnect the legs 88 of the bell cranks has mounted thereon -for relative rotational movement, an outer tubular element 116 as shown most clearly' in FIGURES 2 and 6. Now, the actuating mechanism is completed by means of a series of upright tubular elements 118 welded or otherwise permanently attached between adjacent outer tubular ele' ments 116. Accordingly, huid-actuated reciprocal movement of piston 110 within cylinder 108 will act through tube 112 to turn bell cranks 86m which, in turn, operate through tubes 90, 116 and 11S to accomplish the same motion in the other pairs of bell cranks 86 thus shifting the yieldable frame section 22 relative to the fixed frame 10.

Finally, with reference to FIGURES 1A, 1B and 4, it will be desirable to describe briefly the more or less conventional spring belt driven conveyor assemblies carried by the elevator. All of the grooved rollers 30 are journalled for rotation in longitudinally spaced parallel relation on shafts 120 extending transversely between the side frame elements of the several frame sections. These shafts 120 in the oating frame section 18 of the elevator perform the added function of providing the pivotal connection between the hinged segments 20 thereof. One of the shafts 120 also forms the pivotal connection between the oating and yieldable frame sections. Alter- "wardly fromv each grooved roller tothe adjacent rollers on both sides thereof. Certain of the rollers 122 a'ie drive rollers operatively connected to small electric motors 124 by means of belt drives 126.

Both front and rear side frame elements 34andl 36 of the lixed frame are provided with rollers 30 at the upper end of the elevator arranged in slightly inclined relation to the horizontal and operatively interconnected to one another by spring belts 28, as shown in FIGURE 1B. The upper end of the yieldable frame 22 projects above the corresponding end of the fixed frame a short distance and is provided with an adjustable kicker plate 128 attached between side frame elements 46 for pivotal movement. This kicker plate 128 is inclined rearwardly and functions to direct the packages discharged from between the yieldable and upright frame sections over onto the belts located atop the xed frame.

In closing, note that although the elevatorhas been shown in the form required to elevate tilled bags ver tically, this construction is by no means critical and the yieldable upright frame sections can be inclined at any desired angle above horizontal. Also, the elevator has been described in connection with its primary function of raising lled bags from one level to another; however, it can also be used to lower packaged materials in the same manner, although for this purpose the inclined and floating sections of the frame are preferably connected to the upper ends of the yieldable and upright sections rather than the lower ends as shown.

Having thus described the several useful and novel features of the bag elevator of the present invention in connection with the single specific embodiment thereof illustrated in the accompanying drawings, it will be seen that the many worthwhile objectives for which it was designed have been achieved. I realize, however, that certain changes and modications therein may occur to those skilled in the art within the broad teaching hereof; hence, it is my intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims that follow.

What is claimed is:

l. In a conveyor of the type particularly suited for use in transferring lled bags from one level to another, a fixed frame and a movable frame arranged in spaced `face-to-face relation, a plurality of grooved rollers lincluding a substantially straight section and a curved section arranged in end-to-end relation, the curved section of the movable frame being suspended from the lower end of the straight section and comprising a plurality of hingedly interconnected segments, mounting means interconnecting the straight sections of the fixed and movable frames adapted -to provide for adjustable relative straight-line movement in a direction to vary the spacing therebetween, means interconnecting the straight sections of the fixed and movable frames operative upon actuation to selectively adjust the spacing therebetween while maintaining their relative positioning and to yieldably resist forces tending to spread them apart, said means comprising link means being carried by one of said frame sections and spring-biased means operatively interconnecting said link means with the other of said frame sections, and supporting means carried by one of the curved sections in engagement with the other of said curved sections adapted to permit the hinged segments to raise olf the tlxed frame when an oversize lled bag is passed therebetween.

. Y 7 2.N The conveyor as set forthin claim 1 in which the la'jiountingA means interconnecting the straight sections of the fixed and movable frames comprises tracks depending from one of said straight sections and rollers depending from theaother in rolling engagement with said tracks. 3. The conveyor as set forth in claim l in which the link means comprises, bell crank means mounted for rotational movement on one of the straight sections and having one leg thereof operatively connected to the spring-biased means, and actuating means connected to the other leg of the bell crank means operative upon actuation to rotate same.

4. The conveyor as set forth in claim l in which aligning means interconnect the straight sections of the xed and movable frames adapted to prevent lateral movement therebetween while permitting relative movement toward and away from one another.

5. Ihe conveyor as set forth in claim 1 in whichthe spring-biased meanszyieldably interconnecting one ofthe straight sections with the link means carried by the other straight section comprises, rod means having one end pivotally attached` to the straight frame section and the other end which includes an abutment attached to the link means for relative sliding movement, and spring means interconnecting the abutment and link means in aV manner to yieldably resist -slidable movement of the rod means relative to said link means in a direction to spread the straight sections apart.

linkmeans comprises, bell crank means mounted for rotational movement on one of the straight sections and having one yleg thereof operatively connected to the spring-biased means, and actuating means connected to the other leg of the bell crank means and operative upon actuation to rotate same.

8. The conveyor as set forth in claim 2 in which aligningmeans interconnect the straight sections of the fixed and movable frames adapted to prevent lateral movement therebetween while permitting relative movement toward and away from one another.

9. The conveyor as set forth in claim 2 in which the spring-biased means comprises, rod means having one end pivotally attached to the straight frame section and the other end which includes an abutment attached to the link means for relative sliding movement, and spring means interconnecting the abutment and link means adapted to yieldably resist slidable movement of the rod means relative to said link means in a direction to spread the straight sections apart.

l0. The conveyor as set forth in claim 3 in which the actuating] means Aeo'irlprises "ya cylinder pivotliyattaclied to the. straightfifamefsectioma piston mounted forreciprocal moverr'ie'nt inY the, cylinder-and p'ivotally Vattached to the leg of ythe bell crank means,` andfme'ansoperative to reciprocatefthe piston within the cylinder. y

ll. Theconveyor as set forth inclaim 3 in whichthe bell crank means comprises at least two bell cranks mountedV for rotational movement on the straight section of the- Xed frame and a rigid element interconnecting the cranks for conjoint movement.

12. The conveyor as set forth in claim 3 in which aligning means interconnect the straight sections of the fixed and movable frames adapted to prevent lateral movement therebetween while permitting relative movement forward and away from one another.

13. The conveyor as set forth in claim 3 in whichthe spring-biased meansv comprises, rod means having one end pivotally attached to the straight frame section and the other end which includes an abutment attached to the linkrneans-for relative sliding movement, and spring means interconnecting the abutment and link means adapted to yieldably resist slidable movement ofthe rod means relative to said link means Vin a direction to spread the straight sections apart. p

14, The conveyor as set forth in claim 4 in which the aligning means comprises an arm pivotally attached to one straight sectionand extending toward the other, and a sleeve attached to the other of the straight frame sections for rotational movement and positioned to slidably receive the arm.

15. The conveyor as set forth in claim 4 in which the spring-biased means comprises, rod means having one end pivotally attached to the straight frame section and the other end which includes an abutment attachedto the link means for relative sliding movement, and spring means interconnecting the abutment and link. means adapted to yieldably resist slidable movement of the rod means relative to said link means ina direction to spread the straightsections apart.

16. The conveyor as set forth in claim 5 in which the link means comprises, bell crank means mounted for rotational movement on one of the straight sections and having one'leg thereof operatively connected to the springbiased means, andactuating means connected to the other '-leg of the bell crank means and operative upon actuation to rotate same.

References Cited in the ile of thisipatent UNITED STATESv PATENTS' 551,509 Paul Dec; 17, 1895 830,588 Hanson Sept. 11, 1906 2,490,381 Shields Dec. 6, 1949 FOREIGN PATENTS 91,536 Norway Apr. 21, s 

